| タイトル | Gravitational Focusing and the Computation of an Accurate Moon/Mars Cratering Ratio |
| 著者（英） | Matney, Mark J. |
| 著者所属（英） | NASA Johnson Space Center |
| 発行日 | 2006-03-11 |
| 言語 | eng |
| 内容記述 | There have been a number of attempts to use asteroid populations to simultaneously compute cratering rates on the Moon and bodies elsewhere in the Solar System to establish the cratering ratio (e.g., [1],[2]). These works use current asteroid orbit population databases combined with collision rate calculations based on orbit intersections alone. As recent work on meteoroid fluxes [3] have highlighted, however, collision rates alone are insufficient to describe the cratering rates on planetary surfaces - especially planets with stronger gravitational fields than the Moon, such as Earth and Mars. Such calculations also need to include the effects of gravitational focusing, whereby the spatial density of the slower-moving impactors is preferentially "focused" by the gravity of the body. This leads overall to higher fluxes and cratering rates, and is highly dependent on the detailed velocity distributions of the impactors. In this paper, a comprehensive gravitational focusing algorithm originally developed to describe fluxes of interplanetary meteoroids [3] is applied to the collision rates and cratering rates of populations of asteroids and long-period comets to compute better cratering ratios for terrestrial bodies in the Solar System. These results are compared to the calculations of other researchers. |
| NASA分類 | Astrophysics |
| 権利 | No Copyright |
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